People who inject drugs (PWID) and live with HIV infection often experience double stigmatization. Stigma, the exclusion and dehumanization of individuals in an undesirable social category, may have adverse effects on risk behaviors and health care utilization among PWID. With the SCRIPT (Stigma Coping to Reduce HIV risks and Improve substance use Prevention and Treatment) study, I seek to extend my expertise in addiction medicine and public health to adapt and evaluate interventions addressing the double stigma for PWID living with HIV through these training goals: 1) to apply behavioral theories to understand and address stigma among PWID living with HIV; 2) to analyze stigma and its relation to HIV risks and health care utilization; 3) to acquire competence in the adaptation of a stigma-reduction intervention; 4) to gain expertise in planning and implementing a pilot study of this intervention. Stigmatizing attitudes by others lead to self-stigma, which can have an adverse impact on risk behaviors, addiction treatment and HIV care seeking. Yet, self-stigma has received limited attention in studies conducted among HIV-infected PWID. The SCRIPT study proposes to make use of existing data from NIH-supported studies with HIV-infected PWID in Russia to examine factors affecting the double stigma and its role in substance use and health care utilization in this key population. I also propose to begin to address the problem by adapting and pilot-testing a stigma intervention. In the mentored K99 phase, I will conduct secondary analysis of existing quantitative data from HIV-infected PWID in Russia (n=360) and examine substance use and social factors that affect HIV self-stigma, substance use self-stigma, and stigma's role on health care utilization and risks for HIV transmission. To enhance our understanding of how to address these issues, I will conduct a qualitative study to further explore potentially modifiable aspects of stigma. This will inform the adaptation of an intervention for PWID living with HIV to address stigma. The training and the mentored research related to the SCRIPT study will be essential to my transition to independent stigma researcher. For the R00 phase, I propose to adapt and pilot- test a stigma intervention to target PWID to empower them to cope with shame and avoidance related to stigma. This pilot study will lay the base for an R01 application for a larger randomized control trial of a stigma intervention for PWID.